The present invention relates generally to stormwater drainage systems and, more particularly, to a novel system for filtering sediment and debris from stormwater flowing through a gutter inlet and gravitationally therefrom into a catch basin therebelow.
Stormwater drainage systems are commonplace and, indeed, are mandated for virtually all new building construction subject to the regulations of municipal and county building codes throughout the United States. Essentially, a stormwater drainage system comprises a series of catch basins strategically located according to the topography of a given region under development, with the catch basins emptying into drainage pipes leading to existing streams, creeks, lakes or rivers. In the construction of streets in new building developments, catch basins are required to be constructed below grade alongside the streets to receive stormwater runoff via basin inlets formed in roadside storm gutters.
The growing awareness of environmental conservation issues over recent decades has raised awareness of the significant erosion of bare land which can occur during the course of building construction as a result of stormwater drainage over the bare land. Eroded soil in the form of silt and sediment along with other debris can be carried in significant quantities by stormwater runoff along street gutters and into stormwater drainage systems, sometimes to such a significant extent to clog stormwater catch basins and drainage pipes, and in any event taxing the capacities of and polluting existing streams, creeks, lakes and rivers. As a result, most building codes regulated by municipalities and county building offices have implemented regulations requiring various steps to be taken to prevent or at least mitigate stormwater erosion of soil during building construction, including steps such as the erection of silt fences.
Despite these measures, stormwater runoff still carries a not insignificant amount of silt, sediment and other debris into storm drainage systems. As a result, some form of filtering device is now generally required to be installed in gutter inlets into stormwater catch basins during the course of construction projects to attempt to prevent such debris from entering stormwater drainage systems. Various such filtration devices have been proposed, including for example devices described in U.S. Pat. Nos. 5,403,474; 5,632,888; 5,954,952; 6,709,579; and 6,824,677 and published U.S. Patent Application No. 2004/0112811. While many of these devices may be generally effective for their intended purpose and function, the devices which have achieved commercial use tend to be disadvantageously heavy, bulky and unwieldy. Furthermore, in order to prevent the force generated by stormwater runoff, which can be significant during periods of heavy rain, the filtering medium commonly used in these devices tends to be heavy to assist in holding the devices in place. In turn, the filtration medium also tends to impede the free flow of the stormwater runoff which can result in flooding of the adjacent gutters and streets as water is restricted from entering the catch basins.